What is a Computer Network?

A computer network is a system of interconnected computing devices (computers, servers, smartphones, printers, routers) that communicate with each other to share resources, data, and services. Networks can be classified by size: PAN (Personal Area Network — Bluetooth, USB, a few meters), LAN (Local Area Network — a building or campus), MAN (Metropolitan Area Network — a city), and WAN (Wide Area Network — countries/global, e.g., the Internet). Networks enable resource sharing (printers, storage), communication (email, VoIP), centralized management, and cost savings. The Internet is the world's largest public WAN, connecting billions of devices globally.